TUSB2046B: USB HUB Reset Timing

HI Heeseon:

  Where did you find above reset circuit?

   You just need to add 0.1uF  or 1uF cap on RESET pin .

Regards

Brian

Hi Brain, Thank you for your time!

I used 10K and 0.1uF cap on RESET pin at the first.

I made 10 boards. In 6 boards Linux cannot detect usb Hub.

For the solution, I found these forums : 

TUSB2046B / power-on RESET timing - Interface forum - Interface - TI E2E support forums

TUSB2046 reset condition - Interface forum - Interface - TI E2E support forums

After changing 10K-0.1uF to 15K-1uF, all hubs are detected.

There comes the same problem while doing some power on-off test.

Turn the board on again after few minutes, it works well again. 

Is there any timing conditions between DP0 signal and reset signal?

I have 10k Pull-Up in DP0 Pin(1).

I'd like to know why the DP0 stays low at the beginning.

From now, DP0 signal goes high almost 150ms after 3.3V in.

Will it be okay the reset signal goes high  after the DP0 high?

(3.3V in -> after 150ms -> DP0 high -> Reset High) 

Heeseon Kim said:

3.3V in -> after 150ms -> DP0 high -> Reset High

this sequence should work.

Best

Brian